A Vietnamese employee was shot dead and another wounded while they were drinking with the owner's son at a seafood restaurant in Bang Khunthian district, Bangkok, in the early hours of Wednesday.
The fatal shooting occurred at Khrua Thabthim seafood restaurant in Tha Kham area.
It was reported to police about 3.30am.
Police found a dead man lying in a pool of blood on the restaurant floor. He had a single gunshot wound to his head. Six empty bottles of beer were on a nearby table.
Police named the victim as Hong Van Duc, 28, a Vietnamese national. He worked at the restaurant.
Another Vietnamese employee had been shot in the chest and in the back but was still alive. He was rushed to a nearby hospital.
Police said the two victims had been drinking with the owner's son after the restaurant closed. The man had become angry and allegedly suddenly fired one shot at Hong Van Duc, hitting him in the head and killing him.
He then allegedly shot the other Vietnamese employee in the chest, and again in the back as he tried to flee. The shooter then fled the restaurant.
Police were examining security camera recordings.
On Wednesday morning, a man identified only as Thanakorn turned himself in to police after his family arranged for his surrender. He was being questioned.